In the related art, a semiconductor light emitting device is disclosed which includes a group III nitride semiconductor layer of a stacked structure having an n-type layer, a p-type layer, and an emission layer interposed between the n-type layer and the p-type layer. The emission layer has a multiple quantum well (MQW) structure in which an InGaN layer (quantum well layer) and a GaN layer (barrier layer) are alternately stacked over a predetermined period.
In the semiconductor light emitting device including an emission layer having an MQW structure in which a quantum well layer and a barrier layer are alternately stacked over a predetermined period, holes are injected from the p-type layer to the emission layer and electrons are injected from the n-type layer to the emission layer. The holes and the electrons are then recombined in each quantum well layer to generate light (hereinafter, the recombination in the quantum well layer will be referred to as “radiative recombination”).
However, when each barrier layer is doped with an n-type impurity, holes and electrons may be recombined in the barrier layer (which includes non-radiative recombination that does not entail radiation) (hereinafter, the recombination in the barrier layer will be referred to as “non-radiative recombination”), so that the holes may be gradually consumed in a stage before reaching the quantum well layer. Thus, the radiative recombination in the quantum well layer is not sufficient, which may cause a failure in obtaining sufficient brightness and a desired peak emission wavelength.